Method of forming strip products from theremoplastic materials

Abstract

A method of forming an elongated trim strip product by extruding a first strip of thermoplastic material from a die having an outlet with an area at least substantially as great as the desired cross-sectional area of the strip product in planes perpendicular to the direction of extrusion. Immediately subsequent to the step of extruding and while the extruded strip is still in a plastic state, it is passed longitudinally between cooperating forming rolls to shape the cross section of the extruded strip to the desired shape and cross section of the strip product. While the extruded strip is passing between the cooperating forming rolls, a backing strip of foil or thin metal is directed between the rolls in alignment with the extruded strip to bond the backing strip to the extruded strip. In a second embodiment, one or more cables of high strength flexible material, such as metal wire, are joined to or embedded in the extruded strip during the extrusion process to function as a pulling mechanism for moving the extruded strip through a cooling bath without stretching or deforming the extruded strip. After cooling, the cables can be severed from the strip if desired.

Having thus described the invention, it is claimed: 
     
       1. A method of forming an elongated trim strip comprising the steps of: extruding a first strip of thermoplastic material from a die having an outlet with an area at least substantially as great as the desired cross-sectional area of the strip in planes perpendicular to the direction of extrusion;   immediately subsequent to the step of extruding and while the extruded strip is still in a plastic state, passing the extruded strip longitudinally between cooperating forming rolls to form shape the cross section of the extruded strip to a desired shape and cross section;   while said strip is being extruded and its cross section formed, joining a length of flexible cable to extend longitudinal of the strip in a continuously bonded relationship thereto;   forming a web between said strip and flexible cable, said web adjacent said cable;   subsequently using the flexible cable to transfer the extruded and formed strip through a cooling bath; and   severing the web and cable from the strip by cutting between the extruded strip and adjacent web thereby providing an edge portion on said strip where said web was connected.   
     
     
       2. The method as defined in claim 1 wherein the flexible cable is severed from the extruded and formed strip after completion of the cooling step. 
     
     
       3. The method as defined in claim 1 wherein the flexible cable is joined to the extruded strip by a thin web of thermoplastic material extruded simultaneously with said strip along an edge thereof. 
     
     
       4. The method as defined in claim 1 wherein the flexible cable is joined to the extruded strip prior to passing the strip through the cooperating forming rolls. 
     
     
       5. The method as defined in claim 1 wherein the flexible cable is joined to the extruded strip while the extruded strip is passing through the cooperating forming rolls. 
     
     
       6. The method as defined in claim 3 wherein said cable is joined along a longitudinal edge of the strip by thin web of thermoplastic which is severed from the strip after completion of passage through the cooling bath. 
     
     
       7. The method as defined in claim 6 including directing the cable into bonded relationship with the strip simultaneously with the step of extruding. 
     
     
       8. A method of forming an elongated trim strip having a predetermined cross-sectional configuration transversely of its longitudinal axis comprising the steps of: extruding a first strip of hot molten thermoplastic material from a die having an outlet corresponding to the desired predetermined cross-sectional configuration;   subsequent to the extruding step and prior to significant cooling of the extruded strip joining a length of flexible metal cable continuously along a longitudinal edge of the extruded strip;   forming a web between said strip and flexible cable, said web adjacent said cable;   conveying the extruded strip through a cooling bath by applying pulling forces to the cable; and   thereafter, severing the web and cable from the strip by cutting between the extruded strip and adjacent web thereby providing an edge portion on said strip where said web was connected.   
     
     
       9. The method as defined in claim 8 including the step of extruding a thin continuous web of material along a longitudinal edge of the strip and using the extruded web to join the cable to the strip. 
     
     
       10. The method as defined in claim 9 including the step of shaping the extruded strip to a final desired shape by applying forming rolls thereto prior to conveying the extruded strip through the cooling bath. 
     
     
       11. The method as defined in claim 10 wherein said cable is extruded into the thin continuous web. 
     
     
       12. A method of forming an elongated trim strip for a vehicle comprising the steps of: providing a thermoplastic material for extruding said trim strip, said thermoplastic material being extruded through an extrusion head and a die;   providing a flexible cable, said flexible cable being passed through said extrusion head and said die such that said flexible cable emerges with said thermoplastic material, at least partially disposed within said thermoplastic material, thereby forming an extruded strip having a desired shape and cross section with said cable embedded therein;   forming a web between said strip and flexible cable, said web adjacent said cable;   subsequently using the flexible cable to transfer the extruded strip through a cooling bath;   thereafter, severing the adjacent web and cable from the strip by cutting between the extruded strip and adjacent web thereby providing an edge portion on said strip where said web was connected.